Staplers



Nov. 11, 1958 w. JOPP 2,8 2

' STAPLERS Filed Oct. 8, 1956 2 sheets-sheet 1' I NVEN TOR IIZIZZeJ'ofopp.

Nov. 11, 1958 w. JOPP 2,859,442

STAPLERS Filed Oct. 8, 195a '2 Sheets-sheaf. 2

IN VENTOR Waiter c/opp United States Patent F STAPLERS Walter Jopp,Lahr, Germany, assignor to Skrebba-Werk K. (2.,- Lahr-Schwarzwald,Germany Application October 8, 1956, Serial No. 614,405

8 Claims. (Cl. 13)

This invention relates to staplers and particularly to certainimprovements in those staplers provided with a staple supporting rail, ahold-down member for said rail and forming therewith a staple magazine,and a staple pusher, and in which the retractionof the staple pushercauses the opening of the stapler parts to permit loading staples or toremove troubles which may have caused faulty operation.

In conventional staplers of the type described, the automatic opening,through retraction of the staple pusher, is accomplished by provision ofa locking yoke on the staple supporting rail and a recess in thehold-down member in the region of the pivot, the yoke being coupled tomove with the staple pusher against the direction of staple feed, so asto fall into the recess and permit the stapler parts to openautomatically.

One disadvantage of these known arrangements is that the hold-downmember which is pivotally connected to the staple supporting rail cannotbe opened sufliciently to give free access to the entire length of thestaple supporting rail in order to insert new staple wire sticks.Furthermore, only limited accessibility is possible to the parts of thestapling mechanism which effect the expulsion of the stapling wire.Another disadvantage of conventional staplers of this type is that theyrequire an additional push spring system acting on the locking yokewhich complicates the mechanism and increases its cost.

It is a primary object of this invention to provide a stapler soconstructed as to obviate the above enumerated disadvantages ofconventional construction.

It is a further object of the invention to provide a simply formed andattacheddevice which normally locks the supporting rail to the hold-downmember in closed position but which is released upon retraction of thestaple pusher to permit automatic opening of the supporting rail andhold-down member, completely exposing the supporting rail for staplerefilling purpose.

A further objective of the invention lies in the provision of animproved spring and support means therefor to separate the staplesupporting rail, hold-down member and stapling arm to open position uponrelease of the above-mentioned locking device.

A still further object of the invention lies in the provision of alocking device formed of an extremely rigid, tiltable locking rail,which carries a locking wedge and is operated by the staple pusher, thelocking rail being held and swingably mounted within the supporting railwithout additional supporting parts.

Another objective of the invention lies in the provision of a staplerhaving an improved hinge spring constructed to hold the staplesupporting rail to the base plate between flexible gripping jaws whichpermit ready engagement and disengagement of these parts, the hingespring and base plate being so formed as to enable ready assemblywithout the need of additional fastening parts.

The novel features that are considered characteristic of the inventionare set forth with particularity in the appended claims. The inventionitself, however, both as 2,859,442 Patented Nov. 11, 1958 to itsorganization and its method of operation, together with additionalobjects and advantages thereof, will best be understood from thefollowing description of specific embodiments when read in connectionwith the accompanying drawings, wherein-like reference charactersindicate like parts throughout the several figures and in which:

Fig. 1 is a side view of a stapler constructed according to theinvention with the hold-down member in an open position and showing theportions in the region of the high pressure spring, the hinge spring andstaple driving blade support in partial cross section;

Fig. 2 is a cross-sectional view of the stapler taken on line 22 of Fig.1 and showing the interlocking arrangement between the staple supportingrail and base plate;

'Fig. 3 is a bottom view of the hold-down member, staple supportingrail, staple feed and locking mechanism assembly, showing the hold-downmember in closed position, certain of the parts being shown in sectionfor clarity; 1

Fig. 4 is a cross-sectional view taken on line 4- 4 of' Fig. 3 and ininverted position corresponding to that of Fig. 3;

Fig. 5 is a bottom view similar to Fig. 3 but showing the assembly atthe moment of release of the locking mechanism;

Fig. 6 is a bottom view similar to Fig. 3 but showing the hold-downmember in opened position and the staple pusher in a completelyretracted position held by the locking mechanism;

Fig. 7 is a cross-sectional view taken online 7-' of Fig. 6; a

Fig. 8 is a section through the staple supporting rail and through thebearings of the locking rail, both in inverted position corresponding tothe positions of Figs. 3-6 but with the locking rail shown in process ofassembly before it snaps into engagement;

Fig. 9 is a section similar to Fig. 8 but showing the locking railengaged;

Fig. 10 is a top view of the base plate of the stapler with its attachedhinge spring;

Fig. 11 is a longitudinal section through the base plate of the staplershowing the attached hinge spring and taken on line 1111 of Fig. 10;

Fig. 12 is a cross section of the base plate through the holding lug forthe hinge spring taken on line 1212 of Fig. 10;

Fig. 13 is a perspective view' of a'modified base plate and hinge springassembly, and

Fig. 14 is a cross-sectional view taken on line 14-14 of Fig. 13.

Referring now to the drawings, specifically to Figs. 1 and 2, a staplerin accordance with the invention comprises a staple supporting rail 1, ahold-down member 2, a stapling arm 4 and a base plate 6 which arehingedly connected to each other by a pivot 5. The staple supportingrail 1 is an elongated channel member of inverted U-shaped crosssection, upon which is seated a supply to staples, not shown. Thehold-down member 2 extends over the staple supporting rail 1 and formswith said rail a staple magazine. The forward, inner, face of thehold-down member 2 is shaped to cooperate with the end face of thesupporting rail 1 to form a staple ejection passage. The stapling arm 4covers the holddown member 2 and is equipped, in the usual manner, witha staple driving blade 3 for individually ejecting each wire staplethrough said ejection passage against a die or matrix oppositelypositioned on the base plate 6.

The stapling arm 4 is biased to a spread position with respect to thehold-down member 2 by a leaf spring 7. The leaf spring 7 passesintermediately through a slot V 3 8 in, and bears against, the hold-downmember 2 while its forward end bears against the stapling arm 4 and itsrearward end, that is, the end next to the hinge 5, rests springingly onthe staple supporting rail 1. Thus, the spring7 effects a doublefunction, namely, to spring upwardly both the stapling arm 4 and thehold-down member 2. The leaf spring 7 is held in fixed position in theassembly by a holding lug 9 on the hold-down member seated in anaperture in said spring. t I

A staple pusher 10 is slidably arranged on thestaple supporting rail 1to push the staples forwardly toward their ejection position. A fingergrip yoke 11 is fastened to the pusher 1 and passes under the supportingrail 1. The grip 11 is positioned below and extends outwardly of thehold-down member 2 so that by means thereof, the pusher may be pulledback from the outside a spring 21 comprises an elongated leaf spring,the rear end of which is bent upwardly. This end is slit in such amanner to form two upturned grip-tongue-like legs, which are springy inall directions, each having projecting support lugs 22 and 23 directedtoward each other and a'similar pair of resting lugs 24 and 25 spacedabove even when the hold-down member is closed. The staple pusher 10 ispressed forwardly in the direction of the staple ejection passage by acoil spring 12, Figs. 3, 5 and 7, and thereby effects the feed of thewire staples to their operating position.

Within the open bottomed channel of the staple supporting rail 1, issupported a tiltbeam-like locking mem- -ber 13, as shown in Figs. 3-9.The member 13 is elongated and of inverted L-shaped cross section which,at its broadest part, completely spans the channel of the supportingrail 1. The base 13a of the locking member 13 is a flat element havingcurved sides and, in assembled position, bears against the inner face ofthe supporting rail 1, as best shown in Fig. 9. The downturned sideflange portion 13b of the member 13 extends along that edge of the base13a which has the longer radius of curvature and is likewise curved. Atthe forward end of the flange 13b is an outwardly projecting locking lug14 which is wedge-shaped with the base'of the wedge at the bottom.

The locking lug 14, in the region of the staple ejection passage andunder the influence of a spring 18, projects through locking slits 15and 16, respectively, Figs. 1 and 5, in the staple supporting rail 1 andthe holddown member 2, holding these parts together in their closedposition (Fig. 3) against the action of the leaf spring 7. At theopposite end, the flange 13b is formed as an inwardly turned control cam17 which lies in the path of movement of an upturned lug 11:: on thegrip yoke 11. When the grip yoke 11 is retracted toward its rearposition, the lug 11a pushes against the flange 13b and cam 17, causingthe member 13 to execute a tilting movement which withdraws the lockinglug 14 from the locking slit 16 of the hold-down member 2 (Fig. 5)thereby opening the staple magazine.

After the grip yoke 11 passes by the control cam 17, the locking member13, under the action of the closing spring 18, is again swung into itsclosed position (Fig. 6) so that the control cam 17 moves in front ofthe lug 11a and blocks the grip yoke 11 together with the staple pusher10 from moving forwardly. When the hold-down member 2 is depressed, itbears against the slanted face of the locking lug 14 which is forcedinwardly and then snaps outwardly into the locking slit 16 to hold thehold-down member 2 closed. The inward movement of the lug 14 causes aswinging movement of the locking member '13 and its control cam 17 torelease the grip yoke 11 together with the staple pusher 10 underpressure of spring 12 for forward movement against the staples in themagazine.

' The supporting of the locking member 13 in the staple supporting raill is accomplished by provision of a positioning lug 19 and a depressedholding nose 20 projecting inwardly from opposite sides of the staplesupporting rail 1. The locking member 13 is inserted in a slantedposition below the holding nose 20 (Fig. 8) and, by depressing, engageswith an opening 130 over the positioning lug 19 of the staple supportingrail. The lug 19 lugs 22 and 23. The support lugs 22 and 23 serve thebottom edges of the staple supporting rail 1 as a springy support whilethe resting lugs 24 and 25 clamp into respective depressions 26 and 27in the staple supporting rail 1. In this manner, the hinge spring 21holds the staple supporting rail 1 against the base plate 6 in adetachably locked position yet permits resiliently opposed downwardmovement of the supporting rail under sta: pling pressure applied to thearm 4.

The base plate 6 has stamped therein an upwardly pressed table 28 andinwardly pressed lugs 29 and 30 which together form a guide into whichthe hinge spring 21 can be slidably inserted from the hinge side 5. Uponinsertion, the hinge spring 21 rests with a cut-out over the fixationlug 31 on the table 28 by means of which it is secured againstaccidental longitudinal movement. The deflection of hinge spring 21 islimited in an upward direction by the guide lugs 29 and 3t) and in adownward direction by the table 28 of the base plate.

A modified base plate and hinge spring assembly is shown in Figs. 13 and14. Here, the hinge spring 21' is pushed through a stamped holding loop33 on the underside of the stamped base plate 32 and is held in positionby a fixation lug 34 which seats in an opening of the spring. In ordertollmit the deflection of the hinge spring 21' in a downward direction,the base plate 32 is provided with a tongue 35 which protrudes throughthe slit-like cut-out of the bent up leg of the hinge spring 21? andserves to support the lower edges of lugs 22 and 23 of the hinge spring21' at the limit of their downward deflection.

It is readily apparent from the foregoing description that the staplerin accordance with the invention is easily operated. When used to stapleobjects together, the sup porting rail 1 and hold-down member 2 are inclosed position, held therein by locking lug 14. Each time pressure isapplied to the stapling arm 4, the staple driving blade 3 presses downon the one wire staple at the forward end of the supporting rail 1,forces it through the papers-or objects to be fastened and presses theends of the staple together in the forming matrix ,on base 6. The hingespring 21 and leaf spring 7 return the parts to ready position for thenext fastening operation;

When it is desired to refill the staple supply on the supporting rail 1or to correct a faulty operation, the grip 11 is merely retracted to theposition shown in Figs. 1 and 6. This tilts the locking rail 13 andreleases lug 14 thus allowing the hold-down member 2 to move to its openposition under pressure of spring 7, giving access to the entire uppersurface of the staple supporting rail 1. When the refill or repair iscompleted, it is only necessary to press the stapling arm 4 downwardlyto return all of the parts to their operative positions with thehold-down member 2 closed over and latched to the supporting rail 1 bylug 14.

Although certain specific embodiments of the invention have been shownand described, it is obvious that many modifications thereof arepossible. The invention, therefore, is not to be restricted exceptinsofar as is necessitated by the prior art and by the spirit of theappended claims. z

That which is claimed as new, is:

1. A stapler comprising a base, a staple supporting rail for supportinga supply of staples, a spring-pressed staple pusher on said supportingrail for urging the staples to ward an ejection position, a hold-downmember surrounding the upper portion of said supporting rail and formingtherewith a staple magazine, a stapling arm over said hold-down member,a hinge pivotally holding said base, supporting rail, hold-down memberand arm together at one end of the stapler, a hinge spring separatingsaid base and supporting rail, a leaf spring separating said hold-downmember, arm and supporting rail, a fulcrumed locking rail rockablysupported within said supporting rail and having a wedge-shaped lockinglug at one end for penetration of aligned slots in said supporting railand hold-down member, the other end of said locking rail being formedwith a cam engageable by said pusher to rock the locking rail andrelease the said-locking lug upon retraction movement of said pushertoward the hinge to permit said leaf spring to move said hold-downmember to an open position giving access to the entire staple magazineand upper surface of said supporting rail, and a spring in saidsupporting rail urging said locking rail to latching position with saidlocking rail cam in the path of said pusher to prevent forward movementof the pusher from its fully retracted position.

2. A stapler as defined in claim 1 wherein said pusher is provided witha fixed finger grip yoke extending below said supporting rail andprojecting outwardly therefrom and from said hold-down member, said yokehaving a flange positioned to bear against said locking rail cam so asto rock said locking rail on its fulcrum upon retraction of said yokeand pusher.

3. A stapler as defined in claim 2 wherein said pusher is spring-biasedaway from said stapler hinge and said wedge-shaped locking lug has aslant surface adapted to be cammed inwardly out of its latching positionby depressing movement of said hold-down member whereby said lockingrail and cam are rocked out of the path of said pusher yoke flangepermitting movement of said pusher away from the stapler hinge underpressure of said pusher biasing spring.

4. The combination, for use in a stapler, of an elongated, invertedU-shaped cross section staple supporting rail pivoted to a hold-downmember at one end and a staple pusher biased away from said pivoted end,with a locking mechanism comprising a fulcrumed locking rail tiltablysupported within said supporting rail, a springbiased locking lug onsaid locking rail adapted to enter aligned slots in said supporting railand hold-down member, and a cam on said locking rail adapted to bearagainst said pusher upon retraction thereof to release said lug fromsaid slots and block return of said pusher.

5. The combination defined in claim 4 wherein said locking railcomprises a flat base having curved side edges and a down-turned flangeextending along one edge with an opening in said flange medially of itslength, said sup porting rail having a projection on one wall spacedfrom the web portion thereof and receiving the edge of the locking railbase therebetween, said supporting rail having an inwardly projectingfulcrum lug on the Wall opposite said projection and removably engagedin said flange opening.

6. The combination, for use in a stapler, of a staple supporting rail, ahold-down member and a stapling arm pivoted together at one end, with aleaf spring biasing said supporting rail, hold-down member and armapart, one end of said spring bearing against said supporting rail nearsaid pivoted end, the other end of said spring bearing against said armand said spring intermediate its ends passing through an opening in saidhold-down member, said spring having an opening and said hold-downmember having a lug fitting into said spring opening to preventlongitudinal movement thereof.

7. The combination, for use in a stapler, of a base, a staple supportingrail, and a hinge spring on said base and flexibly supporting saidstaple supporting rail, said base having a table formed thereon and sidewalls with inwardly projecting flanges, said spring having a flatportion slidably mounted between said table and flanges, said springhaving an opening in said flat portion, an upwardly projecting lug onsaid base table and removably nested in said opening to prevent furtherlongitudinal movement of said spring, said spring having two spacedupturned arms carrying two pairs of opposed, inwardly extending,flexible jaws releasably gripping and supporting said staple supportingrail.

8. The combination, for use in a stapler, of a base, a

staple supporting rail, and a hinge spring on said base and ReferencesCited in the file of this patent UNITED STATES PATENTS Vogel Apr. 14,1942 Vail Sept. 18, 1953

